The document summarizes a study conducted by Sentient Science to evaluate how REWITEC additives could extend the life of gearboxes in GE 1.5MW wind turbines. The study used DigitalClone modeling to simulate the fatigue performance of gearbox components treated with REWITEC's DuraGear W100 additive. The modeling predicted that the additive could increase the life of key components like bearings and gears by factors of 12-159 times. If successful, this treatment could provide wind farm operators an option to extend the useful life of slightly damaged gearboxes and lower maintenance costs. The study aimed to help REWITEC enter the US wind turbine aftermarket by demonstrating the life-extending effects of its add

1. REWITEC Additives to Extend Gearbox Life
Wesley Thomas
Vice President, Major Accounts

2. © 2016 Sentient Science Corporation – Confidential & Proprietary
REWITEC Engagement Summary
Business Challenge to Solve: Project Objective:
WindEurope 2017 - REWITEC Additives to Extend Gearbox Life
Operators seeking to extend the life of GE
1.5MW Winergy 4410.2 GBXs that are slightly
damaged
Develop DigitalClone prognostic model to
quantify the effect of REWITEC DuraGear
W100 treatment of GE 1.5 Winergy 4410
Predict and compare the fatigue performance of
“As Is” components with “To Be” components
with surface roughness inputs from REWITEC
Step 1:
Transfer of Data and
Materials
Step 2:
Load Analysis for Winergy
4410.2 GBX
Step 3:
Bearing and Gear Material
Model Development
Step 4:
DigitalClone Simulation for
Bearings & Gears
Step 5:
GBX Life Extension for
Winergy 4410.2 with
DuraGear W100 Treatment
Step 6:
Final Report & Recommendation

3. Why We Chose GE 1.5MW as Example Case Study
REWITEC seeking
to enter U.S.
Aftermarket
Successful
deployments in
Europe
GE 1.5MW chosen
as ideal platform
for US
WindEurope 2017 - REWITEC Additives to Extend Gearbox Life

4. Technical Step 1 – Transfer of Data and Material
REWITEC Field Trials and Available Data
REWITEC had extensive testing and field trials and approval by GE to be used in
after warranty turbines
REWITEC had the correct inputs measured during the field trials that are inputs
into the DigitalClone modeling process

5. Technical Step 1 – Transfer of Data and Material
REWITEC Test Details for Bearings Roughness Input to DigitalClone Simulation
• FE-8 Test at University Mannheim
• Roughness Analyses by NanoFocus AG
• Test run at load of 80 kN for 80 Hrs
• Surface roughness and weight loss was analyzed after 80 Hrs
WindEurope 2017 - REWITEC Additives to Extend Gearbox Life
FE-8 Test – Gear Oil

6. Case Study - Apache Spiral Bevel Gear Validation
Example of Previous Validation by Sentient to Evaluate Surface Finish
Sentient results matched the Boeing
rotorcraft gear design life under loading
conditions equivalent to those experienced
during the qualification testing
DigitalClone assists in increasing the gearbox
ratings
WindEurope 2017 - REWITEC Additives to Extend Gearbox Life
Load
Case
Weibull,
Life/Eta
Weibull,
Slope
300 HP Run-out Run-out
1021 HP 5.14E+07 1.72
1379 HP 1.26E+07 3.32
2042 HP 7.49E+06 3.84
1731 HP 2.97E+06 4.28
Surface stress = -1200 MPa
Surface stress = -1000 MPa
1E+6 4E+6

7. Technical Step 2 – Gearbox Load Analysis
DigitalClone System and Component Models
Multi-body Dynamics system model was
created in Modelica that translates forces
from the hub to the individual components.
Wind loads are being applied on DigitalClone
MBD system model to calculate global forces
and moments on individual components.
WindEurope 2017 - REWITEC Additives to Extend Gearbox Life
Multi-body Dynamics (MBD)
GBX Loads and Life
Forces and
Moments
Wind Turbine
Operational Data
BOM
Oil Properties
Geometry&
Configuration
GBX Prognostic Model

8. Technical Step 3 – Material Model Development
Based on Winergy 4410.2 Material Analysis
To obtain the following technical details from gears and bearing
segments as inputs for DigitalClone Model
• Grain size and morphology
• Case microstructure, core microstructure, case-core transition region
microstructure
• Defects, non-metallic inclusions size distribution, if any
• Material imperfections, retained austenite, grind burn etc.
• Residual stress analysis
• Surface roughness analysis
WindEurope 2017 - REWITEC Additives to Extend Gearbox Life
EDM Sectioned Bearing Segment

9. Technical Step 4 – Mixed EHL Model
Lubrication Testing & Surface Treatment
WindEurope 2017 - REWITEC Additives to Extend Gearbox Life

10. Technical Step 5 – DigitalClone Life Simulation
WindEurope 2017 - REWITEC Additives to Extend Gearbox Life
Intermediate Pinion Gear – at 1.5MW rated Power
Contact Stress
1.7 GPa
L10 Life
Operational
Hrs
L50 Life
Operational
Hrs
L90 Life
Operational
Hrs
“As Is” 4,239.70 5.58E+05 1.66E+07
Rewitec “To Be” 54,871.61 8.89E+07 1.06E+10
Life
Improvement 12.9 159.3 633.8
“To Be”
“As Is”
“To Be”
“As Is”
High Speed IMS Bearing DW– Inner Race at 1.5MW rated Power
Ge 1.5 SLE Winergy 4410.2 HSIS DW
bearing life (L10) improved by a
factor of 12.9 with Rewitec
treatment (“To Be”)
Contact Stress
L10 Life
Operational
Hrs
L50 Life
Operational
Hrs
L90 Life
Operational
Hrs
“As Is” 787.7 2,678.1 27,443.9
Rewitec “To Be” 1,405.0 9,928.8 66,809.7
Life
Improvement 1.8 3.7 2.4

11. Technical Step 6 – Life Results
WindEurope 2017 - REWITEC Additives to Extend Gearbox Life
Winergy 4410.2 GBX Life Extension using DuraGear W100

12. WindEurope 2017 - Introducing DigitalClone Live
The REWITEC DigitalClone model can be
applied to the fleet to determine life
extension across specific assets in the fleet
WindEurope 2017 -
REWITEC Additives to
Extend Gearbox Life

13. © 2016 Sentient Science Corporation – Confidential & Proprietary
WindEurope 2017 -
REWITEC Additives to
Extend Gearbox Life
Trade-Off Studies Asset/Customer specific trade-off option to confidently
predict impact on life/ROI (e.g. gearbox replacements)
ROI Optimization
All trade-offs based
on ROI at the
individual asset
level/group,
maximizing ROI for
the fleet.
REWITEC Upgrades
as Operator Option

14. © 2016 Sentient Science Corporation – Confidential & Proprietary
Additional Use Cases of REWITEC DigitalClone Model
Apply to Other Gearbox Types (Non GE 1.5MW Winergy 4410)
WindEurope 2017 - REWITEC Additives to Extend Gearbox Life
Supplier 1
Supplier 2
Supplier 3
Supplier 4
Supplier 1
Supplier 2
Supplier 3
Supplier 4
5 years 10 years 15 years 20 years

15. © 2016 Sentient Science Corporation – Confidential & Proprietary
Additional Use Cases of REWITEC DigitalClone Model
Apply to Other Gearbox Types (Vestas, Siemens, Acciona, Gamesa Turbines)
WindEurope 2017 - REWITEC Additives to Extend Gearbox Life
Gearbox
Winergy 4435
Winergy 4456
Hansen EH 802
Hansen EH 804
Moventas PLH
GPV 442
Turbine
Siemens 2.3MW
Vestas V82
Vestas V90
Vestas V80
Siemens 3.6MW
Acciona 1.5MW

16. © 2016 Sentient Science Corporation – Confidential & Proprietary
Additional Use Cases of REWITEC DigitalClone Model
How Much Can REWITEC Grease Extend Main Bearing Life?
WindEurope 2017 - REWITEC Additives to Extend Gearbox Life
Sentient case study provided a low cost solution by improving main bearing L10 fatigue life to
avoid premature failures by changing to better lubricant and implementing superfinish
Opportunity to evaluate REWITEC grease3 Parameter Weibull Reliability Analysis
L10 Life L15 Life L17 Life
Conservative
Case
Best
Case
Conservative
Case
Best
Case
Conservative
Case
Best
Case
Baseline 7.6 yrs. >20 yrs. 15.5 yrs. >20 yrs >20 yrs >20 yrs
Super Bearing 18.4 yrs. >20 yrs. >20 yrs. >20 yrs. >20 yrs. >20 yrs.
Overall, L10 fatigue life improved by a factor of 2.42 for Sentient recommended bearing configuration

17. © 2016 Sentient Science Corporation – Confidential & Proprietary
Additional Use Cases of REWITEC DigitalClone Model
OEMs/ISPs Service/Warranty Optimization and New GBX Upgrades
WindEurope 2017 - REWITEC Additives to Extend Gearbox Life
OEM Fleets under LTSA’s
End of Warranty Management
Alternative to Superfinish for new upgrades and gearboxes

18. © 2016 Sentient Science Corporation – Confidential & Proprietary
Additional Use Cases of REWITEC DigitalClone Model
OEMs/ISPs Service/Warranty Optimization and New GBX Upgrades
WindEurope 2017 - REWITEC Additives to Extend Gearbox Life
DCL identifying failure risk and risk exposure for operators when they are weighing their insurance
contracts and other risk management tools
Reduce Gearbox Failure Rates and Risk Exposure – Translate to Lower Premiums for Owner
Operators
Data Driven Forecast Year 5
Under Budget
Unknown Risk
No Corrective Actions
Cumulativefailurerate
Time
Material Driven Forecast Year 5
On Budget
Forecasted Risk
Take Corrective Actions
Cumulativefailurerate
Time
Real Future Failure Rate
Forecast
Historical Data
New Failure Rate
Forecast
Historical Data

19. Executive Summary
Sentient Science has a long history of life extension modeling within aerospace and wind
turbine industries for owner-operators
We have helped our wind turbine owner-operator customers identify critical drivers of
gearbox failures, and they have mandated us to deliver how many will fail, what should
they replace it with, and put them in touch with new life extension solutions
REWITEC reached Sentient Science to evaluate how to enter the U.S. wind market after
much field trial and testing in EU and China. Sentient Science life extension study showed
2x-3.3x improvement.
Opportunities for operators to evaluate ROI on their assets
WindEurope 2017 - REWITEC Additives to Extend Gearbox Life

20. Thank you! Learn More and Meet the Team!
Sentient Presentation Schedule WindEurope 2017
1. Introducing DigitalClone Live
2. Duke Energy Case Study
3. Main Bearing RCA
4. How to Value Digitalization
5. DigitalClone Live Product Update
6. Why Data Science Alone Wont Lower the Cost
of Energy
7. Moventas XL Life Extension Program
9. Rewitec Additives to Extend Gearbox Life
10. DigitalClone Bearing Product Release
11. Wind Loads Modeling
12. Data Fusion: Material Science & Data Science
13. Drivetrain Modeling
14. Reducing Costs with Digitalization
WindEurope 2017 - Introducing DigitalClone Live